Seventh-seeded Brian Gottfried and 10th-seeded Dick Stockton made early exits from the $175,000 Washington Star International tennis tournament last night, losing to a pair of Australians known primarily as doubles players.

Stockton, who had not played a match in three weeks, quickly lost to Kim Warwick, 6-4, 6-3, as he repeatedly missed ground strokes and became the the first seeded player eliminated on the opening day of play.

Gottfried followed, but in completely different fashion, as he lost the best match of the day to Geoff Masters, 6-2, 4-6, 6-4, after leading 2-0, 40-0 in the final set.

"The third game of the last set was the crucial one for me," Masters said, exhausted after the two-hour match. "If he had won the game it would have been 3-0 and I don't think I would have caught him. But after I won that game my serve came back and I got stronger."

Gottfried, runner-up here in 1977, could not come up with the big points in spite of encouraging shouts from many in thr crowd of 3,000. He ended the match by netting two volleys, then watching helplessly as Masters nailed an overhead at 40-30 to eliminate him.

Warwick, a pugnacious 27-year-old who has made his biggest headlines in recent years with his temper rather than his tennis, benefits from a plethora of unforced Stockton errors.

"The only thing that surprised me was that I played so badly," Stockton said. "I played much better in practice than I did in the match. I couldn't believe how many errors I made."

While Stockton struggled in the relative cool of the evening, four other seeds advanced under a blazing sun made hotter by the oppressive humidity.

Only the 14th seed, Hans Gildemeister of Chile, was extended to three sets.

The other three seeds who played in the afternoon did not struggle.

Ninth-seeded Pat DuPre, who reached the Wimbledon semifinals 10 days ago, said he played well enough to win against 17-year-old Ben Testerman, 6-4 6-4.

Eleventh-seeded Eliot Teltscher, a 20-year-old Californian ranked 20th in the world, had the easiest match of the day, routing Richard Meyer, 6-1, 6-4. Butch Walts, the 16th seed, also won in straight sets, beating Bruce Nichols, a late replacement for Brian Fairlie, 6-1, 7-6.

Fifteenth-seeded Marty Riessen was the only seeded player to survive an evening match, beating Mike Grant, 6-3, 6-7, 6-4.

The opening day of the tournament was marred slightly by a series of minor incidents as the field of 64 began its march toward Sunday's final, which will bring the winner $24,500.

Among those incidents were:

The sudden departure of Chevy Chase's Fred McNair IV. Trailing Australia's Alvin Gardiner, 4-6, 5-5, in the first match of the day, McNair walked to the sidelines, picked up a towel and threw up. He then defaulted the match.

An errant throw across court by a ball boy that struck umpire Jim Stennett square on the bridge of the nose and knocked his glasses flying. Stennett, slightly dazed, recovered his glasses and continued.

The ending of the Walts-Nichols match that came, not on a shot by either player, but a penalty point. Frustrated over missing a shot to go down 6-2 in the second-set tie breaker, Nichols batted a ball over the fence. He was promptly given an automatic penalty point. That made the score 7-2, ending the set and the match.